:root {
  --fg: #1f2430;
  --fg-soft: #5a6272;
  --bg: #f7f8fb;
  --card: #ffffff;
  --accent: #3b6cf6;
  --line: #e6e9f2;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: "HarmonyOS Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.75;
}

.hero {
  padding: 72px 24px 56px;
  text-align: center;
  background: linear-gradient(160deg, #16203a 0%, #2a3b6e 55%, #7b5ea7 100%);
  color: #fff;
}

.hero h1 { margin: 0; font-size: 40px; letter-spacing: 2px; }
.hero h1 span { display: block; margin-top: 8px; font-size: 15px; font-weight: 400; letter-spacing: 3px; opacity: .75; }
.hero .tagline { margin: 20px 0 6px; font-size: 17px; opacity: .95; }
.hero .sub { margin: 0; font-size: 14px; opacity: .7; }

main { max-width: 820px; margin: 0 auto; padding: 8px 24px 48px; }

section {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 24px 26px;
  margin-top: 24px;
}

h2 { margin: 0 0 12px; font-size: 19px; }
h3 { margin: 22px 0 8px; font-size: 16px; }
p { margin: 0 0 10px; }

.tagline, .sub { color: inherit; }
.note { color: var(--fg-soft); font-size: 14px; }

.features { margin: 0; padding-left: 20px; }
.features li { margin: 6px 0; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

footer {
  max-width: 820px;
  margin: 0 auto;
  padding: 0 24px 56px;
  color: var(--fg-soft);
  font-size: 13px;
  text-align: center;
}
footer .copyright { margin-top: 12px; }
footer .beian { margin-top: 6px; }

@media (max-width: 480px) {
  .hero { padding: 56px 20px 44px; }
  .hero h1 { font-size: 30px; }
  section { padding: 20px; border-radius: 14px; }
}